JP2010051940A - Method for printing multi-color and full color image on ceramic substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for economically printing a high quality and high density image on a ceramic substrate by using a burnt pigment and an inkjet printer. <P>SOLUTION: A multi-color or full color image is printed by repeating printing cycle including three steps of a first step of coating the entire surface of a ceramic substrate with an alcohol-impenetrable water-soluble resin, a second step of printing a continuous adhesive image on the coated ceramic substrate by jetting an adhesive ink containing an alcohol as a solvent, and a third step of printing a burnt pigment image by depositing a burnt pigment on the adhesive image. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for printing on ceramic substrates such as ceramic tiles.

  Conventionally, printing on ceramics is performed by repeating screen printing for each color using paste-like ink containing a fired pigment on a transfer paper made by coating a water-permeable base paper with a water-soluble resin such as dextrin. After that, a cover coating with a resin is performed, and then the printing layer is transferred to the ceramic substrate by a conventional water transfer. That is, it is a method in which transfer paper is immersed in water, the water-soluble resin on the surface is melted, and only the print layer holding the film form is floated in water by the cover coating, and it is received and adhered to the ceramic substrate. . After that, it may be dried and fired. Since this method is plate-making printing, it requires plate-making work for each color and cannot cope with single-item or small-lot production. Moreover, since screen printing uses a screen mesh, there is a limit to faithfully reproducing a photographic image.

  In order to solve this, application of electrophotography has been attempted. That is, the method includes a method of printing a fired pigment image on the transfer paper by a single color copy operation by including a fired pigment in a laser printer toner. This method has an advantage that it is very excellent in resolution and gradation and is simple. However, there is a limit to the ratio of the calcined pigment that can be contained in the toner, the printing density is limited, and the calcined pigment that is a hard mineral damages the organic photoconductor, so the photoconductor is replaced at an early timing. There are problems such as necessity, toner cost is very expensive, and printing size is limited to A3 size at the maximum. Also, since the coloring material is mineral, it lacks transparency, so there is a limit to the method of expressing multiple colors with subtle color overlays like ordinary organic toners, and the basic four colors of printing are red and green. It cannot be expressed vividly. For this purpose, a special color (a specially selected and mixed mineral is used to express the color) must be used, but such a response is not possible with a laser printer.

  On the other hand, a method of spraying an ink-jet ink in which finely baked pigment is dispersed on a ceramic substrate has been tried for many years. This is the simplest method, but a calcined pigment that is a mineral generally has a specific gravity of 5 or more, and there is a fatal difficulty that it will settle in a short time unless it is refined to nanometer level particles. For example, even if nanometer level can be realized at an enormous cost, the problem that concentration does not come out with fine particles will be stopped. It also has a weak point that it cannot handle spot colors as in the case of electrophotography. In general, ceramic products with a pattern often have dark colors or gold with punches, even if part of the design, and this is not possible, so it is currently used for printing marble patterns on tiles in pastel styles. It is only partially used.

  On the other hand, the present inventor also uses an ink jet printer to spray an adhesive ink using alcohol as a solvent onto a ceramic substrate to make the printed part have continuous adhesiveness, and to attach a baked pigment to the printed part. “Adhesion recording method” (Japanese Patent Laid-Open No. 2005-161828) is disclosed. Since this method uses alcohol as a solvent, the plastic parts around the head and the liquid contact part of the ink path are not affected by a strong solvent, so there is an advantage that a general ink jet printer can be used. There is also an advantage that does not cause health problems in the environment. This method requires labor in the process of spraying and cleaning the fired pigment, but it is possible to achieve high density freely while fully utilizing the high resolution and high gradation characteristic of ink jet, and special color fired pigments are also available. It is a low-cost method that can be used freely and can respond to various designs in earnest.

  However, the adhesion recording method only shows off its excellence when it is limited to printing an image of a certain color. Therefore, an object of the present invention is to provide a method for printing a high-quality multicolor or full-color image using this method.

  As a result of intensive studies, the inventor formed a uniform thin alcohol-impermeable resin layer on the entire surface of the image after printing an image of a certain color by the adhesive recording method. The present inventors have found that the present color image can be satisfactorily overprinted even when the adhesive ink is ejected, and the present invention has been achieved.

  Only when the adhesion recording method is carried out on a fine smooth surface without voids such as the surface of a ceramic tile, a high-quality image can be printed. Adhesive ink jetted onto a concavo-convex surface having a void is absorbed by the void, and an intended adhesive image cannot be printed accurately. Moreover, when a baked pigment is spread | dispersed on it, the fine particle of them will enter into a space | gap, and cannot be removed by injection of compressed air, but remains as thin contamination. The surface on which an image of a certain color is printed is such an uneven surface with many voids. By coating the resin with such voids and irregularities, they are filled and improved to a dense surface, so that the problem that the adhesive ink is absorbed into the voids and the problem of contamination by fine particles are solved.

  On the other hand, the ejected adhesive ink has the property of being infiltrated into an affinity resin layer such as lacquer spray (resin component is nitrocellulose) which is often used and printed. The adhesive image has a problem that the adhesiveness is lost over time. If a resin that is impermeable to alcohol is selected as the resin to be coated at this time, this problem can be prevented. Alcohol is permeable to a wide range of resins, but some water-soluble resins are impermeable. That is, vinyl alcohol resins such as polyvinyl alcohol, cellulose derivatives such as methyl cellulose and carboxymethyl cellulose, natural resins such as starch and dextrin, sodium alginate and the like. A resin layer may be formed by coating an aqueous solution of these resins alone or in a mixture by spray coating or screen printing so as to have a dry thickness of about 1 to 20 microns, preferably about 2 to 10 microns.

  The adhesive ink uses alcohol as a solvent, and uses an alcohol-soluble resin as a solute for imparting adhesiveness. In general, in the production of pressure-sensitive adhesives, solvents such as toluene, MEK, and ethyl acetate, which have strong resin dissolving power, are used, so the selection range of rubber and resin is large, but it is suitable even for a limited number of types. Selection of an alcohol-soluble resin is possible. The specific ink composition includes an alcohol solvent having an appropriate hygroscopic property to prevent clogging of the head, an alcohol-soluble base resin such as acrylic, and, if necessary, an alcohol-soluble plasticizer and A tackifier is dissolved. In addition, in order to maintain continuous adhesiveness, a small amount of high boiling alcohol is also contained. (Detailed in cited document)

  Printing of a full color image by the method of the present invention is realized by repeating a printing cycle of “resin layer formation, adhesive ink jetting, firing pigment spraying / cleaning” four times for each color. Specifically, a full-color image is separated into four primary colors of cyan, magenta, yellow, and black, and a grayscale image printing cycle for each color is repeated four times in the order of cyan, magenta, yellow, and black, for example. Good. If a special color (for example, gold) is added to the image, a fifth printing cycle based on the data may be performed.

  According to the present invention, it has become possible to print a multicolor image including a special color or a full color image on a ceramic substrate with high image quality and low cost in small lot units using an ink jet printer.

  Although there are infinite embodiments in the present invention, only examples of typical embodiments will be described here. Here, the blending ratio of various preparations assumes that the specific gravity of solid resin is 1, and the ratio represents volume%. The base resin is an alcohol-soluble acrylic resin “Elvasite” (trademark, manufactured by DuPont), the tackifier is an alcohol-soluble rosin ester, and the calcined pigment is a four-color set (manufactured by Degussa, Germany) An average particle size of 5 microns) was used. The inkjet printer used was a flat bed type GP-604 (trademark, manufactured by Mimaki Engineering Co., Ltd.) equipped with a piezo Epson head, and the adhesive ink was set only on the black head.

First, an adhesive ink having the following composition was prepared.
Elbasite 4%
Rosin ester 3%
Dimethyl phthalate 3%
Isopropyl alcohol 40%
2-Ethoxyethanol 50%
Next, a 5% concentration aqueous solution of polyvinyl alcohol was prepared, and a resin layer having a dry thickness of 5 microns was formed on a 30 cm square white tile by spray coating. A yellow grayscale image prepared by color-separating a full color image was printed thereon using an adhesive ink. A yellow calcined pigment was sprayed over the entire surface, and excess powder was removed with a brush, followed by cleaning with a jet of compressed air. The same operation was sequentially performed for cyan, magenta, and black. As a result, a full-color image of a fired pigment was printed with high quality and no contamination with a white tile back. When this tile was baked at 850 ° C., no defects such as cracks, pinholes and peeling occurred.

  According to the present invention, it has become possible to print a multicolor or full color image on a large tile at a very short delivery time, in a small lot, and at a low cost. In addition, since high-density colors and special colors can be printed at a very low cost, full-scale designs can be applied to the construction field such as large walls and floors.

Claims (3)

  A first step of coating the entire surface of the ceramic substrate with an alcohol-impermeable resin, a second step of printing an adhesive image using an ink jet printer with an alcohol-based solvent, and the adhesive property. A method for printing a multicolor fired pigment image, comprising repeating a cycle comprising three steps of a third step of printing a fired pigment image by attaching a fired pigment to an image.   2. The method for printing a multicolored fired pigment image according to claim 1, wherein the alcohol-impermeable resin is a water-soluble resin.   The water-soluble resin is a vinyl alcohol resin such as polyvinyl alcohol, a cellulose derivative such as methyl cellulose or carboxymethyl cellulose, a natural resin such as starch or dextrin, or sodium alginate, or a calcined pigment image according to claim 2, Printing method.